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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

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130                                  ALASKAN GLACIER STUDIES
destruction of an interior flat area, similar to, though smaller than, that existing in the Variegated Glacier bulb.
In 1905 the Butler Glacier presented no evidence of recent advance that we recognized, though it is possible that it may have undergone a transformation similar to that of the Galiano Glacier. Such a change, followed by healing through ablation similar to that on the Galiano Glacier would not have been recognized by us in the absence of previous observations or photographs for comparison. There certainly has been no notable advance and breaking of this glacier between 1905 and 1910, for any distinctive change would have been recognizable in our photographs. We may, therefore, assume that unless this glacier passed through a cycle of advance due to the 1899 earthquakes prior to 1905, it has not yet entered upon it.
Observations in 1910 and 1913. In 1910 and 1913, the junior author made distant observations of Butler Glacier from near Nunatak Glacier. It was observed that there was an area of outwash gravels in the depression between the eastern end of Orange Glacier and the piedmont area of Butler Glacier.
As far as visible up its mountain valley Butler Glacier is clear of d6bris. It appeared crevassed in the valley portion in 1910 where no particular crevassing was observed in 1905 or 1909, but there was no increase in this area of crevassing from 1910 to 1913.